Reading raw values is not possible

[hacknus]

The raw values are stored in 16bit signed integers and can be read out. Please implement this in the library as well, currently only unsigned ints are implemented (temperature).

[caternuson]

Can you provide more information about what is needed here. Is this basically a request to make read16() public?

[hacknus]

read16 returns an unsigned 16 bit integer. However in the datasheet it says:

If the RAM is read, the data are divided by two, due to a sign bit in RAM (for example, TO1 - RAM address 0x07 will sweep between 0x27AD to 0x7FFF as the object temperature changes from - 70.01°C...+382.19°C). The MSB read from RAM is an error flag (active high) for the linearized temperatures (TO1, TO2 and Ta). The MSB for the raw data (e.g. IR sensor1 data) is a sign bit (sign and magnitude format)

This means we need to read the raw data and convert it to a sign and magnitude format (signed 16 bit integer). Also, I believe that the error flag for the temperature values is also not implemented.

[caternuson]

OK, still not sure what the request is then. The various read functions take care of all that converting.

[hacknus]

Doesn't the read16 just return the unsigned two's complement instead of the sign and magnitude format? return uint16_t(buffer[0]) | (uint16_t(buffer[1]) << 8); see here.

so we'd need a read16_signed method (private is okay, if there is would be a wrapper like for example readRaw1 and readRaw2).

And I also noticed that the CRC is never verified when reading data. So to put concrete requests:

• implement readRaw1 and readRaw2 which return signed 16 bit integers
• implement the reading of the errorflag for TO1, TO2 and TA
• implement verifying the crc for any data that is read